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    <title>buttmag</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>buttmag</b> -   response of Butterworth filter</p>
    <h3>
      <font color="blue">Calling Sequence</font>
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    <dl>
      <dd>
        <tt>[h]=buttmag(order,omegac,sample)  </tt>
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    <h3>
      <font color="blue">Parameters</font>
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    <ul>
      <li>
        <tt>
          <b>order</b>
        </tt>: integer : filter order</li>
      <li>
        <tt>
          <b>omegac</b>
        </tt>: real : cut-off frequency in Hertz</li>
      <li>
        <tt>
          <b>sample</b>
        </tt>: vector of frequency where <tt>
          <b>buttmag</b>
        </tt> is evaluated</li>
      <li>
        <tt>
          <b>h</b>
        </tt>: Butterworth filter values at sample points</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
    squared magnitude response of a Butterworth filter
    <tt>
        <b>omegac</b>
      </tt> = cutoff frequency ; <tt>
        <b>sample</b>
      </tt> = sample of frequencies</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

//squared magnitude response of Butterworth filter
h=buttmag(13,300,1:1000);
mag=20*log(h)'/log(10);
plot2d((1:1000)',mag,[2],"011"," ",[0,-180,1000,20])
 
  </pre>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p>F. D.  </p>
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